Mexican lime

The Key lime (Citrus × aurantiifolia) is a citrus hybrid (C. micrantha x C. medica) with a spherical fruit, 2.5–5 cm (1–2 in) in diameter. The Key lime is usually picked while it is still green but it becomes yellow when ripe. It is smaller and seedier, with a higher acidity, a stronger aroma, and a thinner rind, than that of the Persian lime (Citrus × latifolia). The Key lime is valued for its unique flavor compared with other limes. The name is derived from its association with the Florida Keys, where it is best known as the flavoring ingredient in Key lime pie. It is also known as West Indian lime, bartender's lime, Omani lime, or Mexican lime, the last classified as a distinct race with a thicker skin and darker green color. Philippine varieties have various names, including dayap and bilolo. The English word lime was derived, via Spanish then French, from the Arabic word ليمة līma, which is itself a derivation of the Persian word limu لیمو. Key is from Florida Keys, where the fruit was naturalized. The Oxford English Dictionary dates the first use of 'key lime' to 1905, in an issue of Country Gentleman, which described the fruit as 'the finest on the market. It is aromatic, juicy, and highly superior to the lemon.' C. aurantiifolia is a shrubby tree, to 5 m (16 ft), with many thorns. Dwarf varieties exist that can be grown indoors during winter months and in colder climates. Its trunk, which rarely grows straight, has many branches, and they often originate quite far down on the trunk. The leaves are ovate, 2.5–9 cm (1–3 1⁄2 in) long, resembling orange leaves (the scientific name aurantiifolia refers to this resemblance to the leaves of the orange, Citrus aurantium). The flowers are 2.5 cm (1 in) in diameter, are yellowish white with a light purple tinge on the margins. Flowers and fruit appear throughout the year, but are most abundant from May to September in the Northern Hemisphere. When in contact with the skin, the Key lime can sometimes cause phytophotodermatitis, in which a chemical reaction makes the skin extra sensitive to ultraviolet light. This particular cultivar is a citrus hybrid, Citrus micrantha × Citrus medica (a papeda-citron cross). C. aurantiifolia is native to Southeast Asia. Its apparent path of introduction was through the Middle East to North Africa, then to Sicily and Andalucia and via Spanish explorers to the West Indies, including the Florida Keys. Henry Perrine is credited with introducing the Key lime to Florida. From the Caribbean, lime cultivation spread to tropical and subtropical North America, including Mexico, Florida, and later California. Since the North American Free Trade Agreement came into effect, many Key limes on the US market are grown in Mexico, Central America and South America. They are also grown in Texas, Florida, and California.